Modified circular common element four-port multiple-inputmultiple-output antenna using diagonal parasitic element

摘要

A four-port multiple input multiple-output (MIMO) antenna with common radiating element is proposed for 2.4 GHz Wi-Fi applications. It comprises a modified circular radiator fed by four identical modified feedlines, partial ground planes, and a diagonal parasitic element (DPE). The parasitic element is used to enhance the interport isolation. The antenna has a 2:1 Voltage standing wave ratio (VSWR) impedance band 2.34-2.56GHz and nearly omnidirectional radiation patterns. The radiation efficiency is more than 79% and gain is 2 dBi at resonant 2.43GHz. The isolation in the given frequency band is 10 dB. At the 2.43GHz, the isolation between adjacent ports (1, 2 and 1, 4) is 14dB and between opposite ports (1, 3) is 12dB. The mean effective gain (MEG)-2.7 dB and envelope correlation coefficient is 0.01. The -10 dB total active reflection coefficient bandwidth is 202MHz. The antenna is designed for a Wi-Fi device and the effectiveness of antenna has been checked for distance of 1/2 feet from the human head. The specific absorption rate (SAR) is found to be 0.17W/Kg by CST simulation tool.